Darwinella pronzatoi Bertolino, Costa & Pansini sp. nov.

urn:lsid:zoobank.org:act: FA17C8DB-1973-4E6F-9AB9-A025F68D38F5

Fig. 15

Etymology

The new species is named after Professor Roberto Pronzato (DISTAV – Università degli Studi di Genova) in recognition of his significant contributions to taxonomic studies on horny sponges.

Type material

Holotype

CHILE – Puerto Cisnes • Seno Magdalena C; 44.631113° S, 72.929130° W; depth 15 m; 5–10 Aug. 2016; Marco Bertolino leg.; on a rocky wall by scuba diving; CILE 100; MSGN 61500.

Description

HABITUS. Encrusting sponge about 5 cm long and 1.5 cm thick, with regular conulose surface. Colour in life bright yellow (Fig. 15A). Live specimens soft, very fragile, showing numerous oscula with low rim (Fig. 15A). Ostia also visible on sponge surface (Fig. 15A)

SKELETON. Structure typical of Darwinella genus with ascending dendritic fibres supporting surface conules. Several dendritic fibres arise from common basal plate. Red dendritic fibres laminated, linear and sinuous, 14–(15)– 16 mm long and 70–(80)–90 μm thick, with opaque core (Fig. 15B); axial core 10–(11)–12 μm thick.

SPICULES. Smooth, straight, slightly curved or sinuous horny styles, with visible axial core (Fig. 15C), 87.5–(436)–830 μm long and 9–(12.5)–16 μm thick; axial core 2.5–(8.3)–13 μm thick.

Habitat

Species lives at a depth of 15 m in a shady area on rocky wall.

Remarks

Up to now, there was no evidence of the presence of the genus Darwinella from the Chilean coasts. Thirteen species belonging to this genus have been described worldwide, eleven of which have multiradiate spicules and one species, Darwinella tango (Poiner & Taylor, 1990), has no spicules. Only two species are characterized by monaxonic spicules: D. gardineri Topsent, 1905, characterised by curved horny oxeas (1600–2000 × 20 μm), and D. oxeata Bergquist, 1961, having horny spined oxeas (530– 2083 × 4.2–29.8 μm). Due to the presence of smooth, straight, slightly curved or sinuous horny styles, D. pronzatoi is clearly different from both these species, therefore it should be considered as a species new to science.